Phonograph sound box



R. HEAD.

PHONOGRAPH SOUND BOX. APPLICATION FILED AUGJ 1920.

1,404,608. t d Jan. 24,1922.

. ROBERT HEAD, or .YONKE UNITED STATES,

PATENT oat-ice.

RS, NEW YORK, ASSIGNOR TO THE ALEOLIAN COMPANY, A CORPORATION OF CONNECTICUT.

PHONOGRAPH SOUND BOX.

Specification 01 Letters Patent. Patented Jan, 24, 1922,

Application filed August 5, 1920. Serial Ito-401,500.

fication, reference being had to the ac-' companying drawings, thereof.

My present lnventlon relates to sound forming a a part boxes for phonographs and the like, whereby the size of the efl ective or vibratable area of the diaphragm can be varied-at will, certain kinds of records being best played with a large diaphragm and others with a smaller diaphragm. The present. invention puts the size of the diaphragm under the immediate control of the user of the instrument, so that he can readily shift from one size to another. The drawings show only one of the preferred embodiments Which my invention is adapted to take. In them, Figure 1 is a full view olf a sound box embodying my invention.

Figure 2 is a rear view'of the same. Figure 3 is a sectional View on the line 33 in Fig. 1 looking in the direction of the arrows.

. Figure 4 is the same, except that the parts have been adjusted to play with the large diaphragm-area, whereas in Fig. 3, the adjustment is for playing with the small diaphragm-area.

Describing now the devices of the drawings:The sound box has the usual body portion made up of a circular back 1, to which is secured a ring 2 having a gasketretaining flange 3. 14 are a ,pair of gaskets snugly retained within the cavity of the box and clampin between them the outer part of the diaphragm 5. The back 1 has the usual central opening through it coincident with the bore of the neck 6, by which the box is secured to the tone-arm or horn of the phonograph.

- 7 and 8 are a pair of small" diameter gaskets, severally mounted in a ring 9 and a ring 10 on opposite sides of the diaphragm.

The inner ring 10 is located in an annular recess 11 in the back, and has three pins 12 spaced 120 degrees apart, projecting slidably through correspondingly located holes through the back.

Similarly the outer ring 9 has three pins 13 projecting slidably through the wall 2 and the'back 1 of the box, preferably as shown radially in line with the aforesaid inner pins 12. Said pins 13 are attached to said ring 9 by means of the bent lugs 14 projecting outwardly from the ring.

Means are provided for adjusting the rings 9 and 10 towards and away fromeach other to clamp the diaphragm between the gaskets 7 and 8 and vice versa to release it,

said means comprising movable cams. acting on the free, exposed portions of the aforesaid pins 12 and 13. For this purpose, there are a pair of oppositely inc-lined cams 15 and 16 for each couple of adjacent pins 13, 14 (compare Fig. 3 or Fig. 4 with Fig. 2).

The cams are supported on a ring 17 which is rotatably mounted on a circular seat on the back 1 of the box and is retained on said seat by the overhanging heads of the screws '18 and 18 (Fig. 2). The ring 17 is provided with an integral handle 19 (Fig. 2) by which the user can give a partial rot-ation to the ring and its supported cams 15 and 16, the extent of said partial rotation being limited by the contact of said handle 19 with the screws 18 and 18 (Fig. 2).

The'inclinededges of the cams 15 and 16 engage corresponding notches 12 and 13 in the adjacent sides of the pins 12 and 13, Since as previously stated, the cams l5 and 16 are oppositely inclined relatively to each other, it follows that a given directional movement of the handle 19 will slide the pins 12 and 13 in opposite directions and therefore will move thegasket rings '9 and 10 in opposite directions-that is, movement of the handle in one direction will cause said gasket rings to clamp the diaphragm as in Fig. .3, and in the opposite direction, will cause them to unclamp and release the diaphragm as in Fig. 4.

In Fig. 4, the diaphragm will play with its largest area because it is clamped only by the large gaskets 14. In Fig. 3, the diaphragm will play with its small area, being clamped by the small gaskets 7 and 8, and will sound with a much higher quality of tone. Thus it is put within the power of the user to vary the quality of the reproduction to suit the record or the individual taste by simply shifting the handle 19.

It will be noted that the diaphragm contact members have a straight line nonrotary movement to and from the dia-' phragm, and therefore have no tendency to rotate the diaphragm which would be objectionable because it would tend to loosen or break the delic-ate'conneotion between the center 0 f the diaphragm and the stylusbar 20.

An additional setor sets of other sizes of gasket-rings could be provided with mec anism similar to the foregoing for their operation to provide still further tonal effects from one and the same sound box.

The purpose of the annular recess 11 is to permit the gasket 8 and ring 10 in the Fig. l'adjustment of the box to be recessed into the back 1 of the box so as to leave the air chamber of the-box unobstructed and therefore non-interferent with the tone proing' ring 10 being greater than that of the other ring 9 so that onmanipulating the handle 19, the gaskets of both ringsimpinge upon the diaphragm simultaneously.

I do not limit myself to the herein disclosed embodiment of my invention, and of course changes can be made within the scopeof what is claimed without departing from the spirit of the invention.

lVhat I claim is:

1. The combination with a sound box and its diaphragm, of means for adjusting the efiective area of the diaphragm to be smaller or larger at will;

2. The combination with a sound box and its diaphragm, of means for clamping the outer.

part of the diaphragm to play with a relatively largearea diaphragm, and means for clampingan inner part of the diaphragm to play with a relatively small area diaphragm.

3. The combination with a sound box and its diaphragm, of means for clamping an inner or an outer part of the diaphragm & its diaphragm, of diaphragm contact memtact with the diaphragm.

bers on opposite sides of the diaphragm movable normally and not parallelly to the plane of the diaphragm, and means for moving said members into and out ofcon- 6. The combination with a sound its diaphragm, of diaphragm contact membox and bers on opposite sides of the diaphragm.-

movable to and away-from said diaphragm,

and means for moving both contact mem-. bers simultaneously away from the dia-v phra-gm, or simultaneously into contact with the diaphragm.

7 The combination with a sound box and its diaphragm, of diaphragm contact members on opposite sides of the diaphragm movable normally and not parallelly to the plane of the diaphragm, and means. for moving both contact members simultaneously away from the diaphragm,'or simultaneously into contact with the diaphragm.

8. The combination with a sound box and its diaphragm, of. diaphragm contact members on opposite sides of the diaphragm with pins projecting slidably through-the back of the box, and movable cam means on the box engaging said pins to move the contact members towards and away from the diaphragm. I

9. The combination with a sound box and its diaphragm, of means for normally clamping the outer part of the diaphragm to play with a diaphragm of relatively large area, and means for clamping or not clamping at will an inner part of the diaphragm to play with a diaphragm of rel atively small area.

10. A mounting as characterized comprising a vibratory diaphragm; means for supporting the same providing a-normal vibrant pitch therefor; and means-for varying the vibrant pitch thereof without subjecting said diaphragm to tension.

11. A mounting as characterized com prising a vibratory diaphragm; means, providing a boundary for determining the normal vibrant area thereof; and means for varying the dimensions of said area without varying the normal form of said dia-I phragm.

12. A mounting as characterized com prising a vibratory diaphragm; means pro viding a boundary for determining the normal vibrant area thereof; and means for varying said area, said latter means embodying opposed clamping members providing fixed boundaries for said area within the. first named boundary.

13. A mounting as characterized comprising a vibratory diaphragm, a plurality of opposed clamping members adapted to vary the effective vibrant area of said diaphragm.

14. In a mounting as characterized comprising a vibratory diaphragm, said diaphragm occupying a normal plane, a pluphragm-area-reducing members mounted at ralit-y of opposed clamping members adapted opposite sides'of the diaphragm, and means to vary the normal vibrant area of said diafor shifting both said members either to- 1 phragm while maintaining said diaphragm ward or away from the diaphragm. 6 in said normal plane. 7 In witness whereof, I hereunto set my 15. The combination with a sound box and hand this 4th day of August, 1920. a diaphragm mounted therein, of dia- 4 ROBERT HEAD. 

